MC68HC05JJ6 Datasheet, PDF (101/216 Pages) Freescale Semiconductor, Inc – General Release Specification Microcontrollers

Parallel Input/Output
7.5.4 Port C Logic
Figure 7-15 shows the I/O logic of port C.
When a port C pin is programmed as an output, reading the port bit
actually reads the value of the data latch and not the voltage on the pin
itself. When a port C pin is programmed as an input, reading the port bit
reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its DDR bit. Table 7-4 summarizes the
operations of the port C pins.
READ $0006
WRITE $0006
WRITE $0002
READ $0002
WRITE $0010
RESET
DATA DIRECTION
REGISTER C
R
BIT DDRCx
PORT C DATA
REGISTER
BIT PCx
PULLDOWN
REGISTER A
BIT PDICx
R
PULLDOWN INHIBIT
MASK OPTION
(ENABLE = 0)
Figure 7-15. Port C I/O Circuit
PCx
15 mA SINK
5 mA SOURCE
CAPABILITY
100 µA
PULLDOWN
DEVICE
MC68HC05JJ6/MC68HC05JP6 — Rev. 3.2
Freescale Semiconductor
Parallel Input/Output
General Release Specification
101